Compare AI models

Specifications
Context windowHow much information the model can work with in one request, measured in tokens — pieces of words or other data. This includes your question, attachments, conversation and reply. Limits can vary by model variant and provider.
1.05M—
API pricingUSD per 1M tokens · lower wins · base tier
Input priceWhat you pay for everything you send the model — your question, plus any documents or earlier conversation you include with it.
$1.00—
Output priceWhat you pay for the text the model writes back. It is normally the dearer half: producing an answer costs more than reading one.
$5.00—
Cached input priceA reduced rate for text you send over and over. If every request starts with the same instructions or the same document, the provider keeps a copy ready and charges less to read it again.
$0.05—
Cheapest inputLowest input rate across every provider on OpenRouter, the lab included. The cheapest endpoint may run a quantised build or a shorter context — see "Available from" on the model page.
$0.50OpenAI—
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
$2.50OpenAI—
$225OpenAI—
Benchmarks
Next.js EvalsNext.js coding — Vercel's open eval of how well AI coding agents build and migrate real Next.js apps — measured as the share of tasks the agent completes successfully. Higher is better.
97%81%
Overview
CompanyOpenAISpaceXSI
Release dateOct 26 2026May 18 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

GPT-6.1 Terra leads Composer 2.5 on 1 of the 1 benchmark they both report (Next.js Evals). Only GPT-6.1 Terra has a verified first-party price for an available API: $1.00 per million input tokens and $5.00 per million output tokens. No currently available pay-as-you-go API rate is tracked for Composer 2.5. Composer 2.5 shipped 161 days before GPT-6.1 Terra, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

On Next.js Evals, GPT-6.1 Terra leads at 97% vs Composer 2.5 at 81%.